I believe that the Companions always auto-level to your current level once they are switched back in. Henchmen do not.
...but they do not!
I finished a quest with Bairdotr and gained 180XP.
8000XP + 180 (Quest) XP = 8180XP
After that, I exchanged Bairdotr with Wolgraff. Wolgraff gained only 10XP. 8000XP + 10 (AutoLevel) XP = 8010XP
Is it a bug?
